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Affected components


Affected versions

6.0.0, 6.0.1, and 6.0.2

Fixed versions



Denial of Service.

A malformed authentication attempt may cause the broker to terminate. The Apache Qpid Broker-J supports a number of configurable authentication providers each supporting various SASL mechanisms. Some mechanisms need (or can be configured to accept) plain-text passwords being sent to the Broker (using the SASL "PLAIN" mechanism). Where the broker has been configured to allow plain-text passwords for authentication it is possible for a client to send a malformed authentication attempt which will lead the broker to terminate due to an uncaught Exception.

Brokers configured to use authentication from the "PlainPasswordFile", "SimpleLDAP", or "Base64MD5PasswordFile" providers are vulnerable if the "PLAIN" mechanism is enabled (by default "PLAIN" will be disabled on non-TLS ports, but enabled on TLS connections).


Users should upgrade their Apache Qpid Broker-J to version 6.0.3 or later. If this is not possible, users can disable the PLAIN mechanism for their authentication manager on versions 0.32 and later by adding "PLAIN" to the list of disabledMechanisms on their authentication provider object.

Note that the SimpleLDAP authentication provider requires PLAIN and so this work around does not apply there.


This issue was discovered by Alex Szczuczko of Red Hat, Inc.